Risk of opportunistic infections in patients with antineutrophil cytoplasmic antibody-associated vasculitis, using a Japanese health insurance database

Abstract

Aim: Opportunistic infections (OIs) adversely affect outcomes in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV). This study aimed to identify the incidence proportion of risk factors for OIs in patients with AAV who were on remission-induction therapy, using a Japanese health insurance database.

Method: This retrospective longitudinal population-based study was conducted using claims data provided by Medical Data Vision Co., Ltd. We defined individuals as AAV cases receiving remission-induction therapy if they met all of the following criteria: (a) having OIs with at least 1 specified International Statistical Classification of Diseases and Related Health Problems, 10th Revision code (M300, M301, M313, or M318); (b) receiving at least 1 prescription of oral corticosteroids (CS) with prednisolone (PSL)-equivalent dosage ≥30 mg/d, CS pulse therapy, immunosuppressive agents or rituximab during hospitalization between April 2008 and April 2017; and (c) at least 7 days of hospitalization while on the above-mentioned therapies. We calculated incidence and proportion of OIs during the year following remission-induction therapy and the adjusted odds ratio (OR) using a logistic regression model.

Results: We included 2299 patients with AAV in this study. OIs occurred in 460 patients (20.0%), with the most frequently occurring OI being cytomegalovirus infection (n = 122, 6.5%). After adjusting for covariates, age by decade (OR 1.24, 95% CI: 1.12-1.36), daily PSL dose per 10 mg (OR 1.16, 95% CI: 1.08-1.25), and CS pulse therapy (OR 1.29, 95% CI: 1.04-1.60) were found to be significantly associated with occurrence of OIs.

Conclusion: Older age and corticosteroid use were found to be significant risk factors for OIs in patients with AAV on remission-induction therapy, using a health insurance database.

Keywords: antineutrophil cytoplasmic antibody-associated vasculitis; drug treatment opportunistic infection; epidemiology; risk.